Thanksgiving Day is a national holiday celebrated primarily in the United States and Canada
as a day of giving thanks for the blessing of the harvest and of the
preceding year. Several other places around the world observe similar
celebrations. It is celebrated on the fourth Thursday of November in the
United States and on the second Monday of October in Canada.
Thanksgiving has its historical roots in religious and cultural
traditions, and has long been celebrated in a secular manner as well.

The USA has been celebrating Thanksgiving Day IN ITS PRESENT FORM for the last 63 years. Just as today, the idea behind Thanksgiving Day at the end of November was to provide an economic boost to Christmas sales.

On December 26, 1941, President Franklin D. Roosevelt
signed a joint resolution of Congress changing the national
Thanksgiving Day from the last Thursday in November to the fourth
Thursday. Two years earlier, Roosevelt had used a presidential proclamation to try to achieve this change, reasoning that earlier celebration of the holiday would give the country an economic boost.